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据报导,加拿大在防治多年来危害冷杉林的害虫——云杉芽卷叶蛾方面,取得了进展. 七二年夏季,在魁北克省东部二千万亩(八百万公顷)的云杉等林内,云杉芽卷叶蛾大量蔓延,严重影响林木的正常生长.过去,防治这种害虫多用化学药物喷洒,后来则使用苏云金杆菌.苏云金杆菌虽无害于益虫、植物、鱼类和其他动物,但对于消灭贪吃的云杉芽卷叶蛾幼虫来说,收效太慢,必
It has been reported that Canada has made progress in the prevention and control of the pest Spruce-Buds, a pest that has been detrimental to the fir forests for many years. In the summer of 1972, in the forests of 20 million mu (eight million hectares) of spruce in the eastern part of Quebec, Spruce bud leafworm large spread, seriously affecting the normal growth of trees in the past, the prevention and control of this pest chemical spraying, and later the use of Bacillus thuringiensis. Although Bacillus thuringiensis harm beneficial insects, plants, fish and other animals, but for the elimination Greedy spruce bud leafworm larvae, the effect is too slow, must